Geology and lode gold deposits of the Nuka Bay area, Kenai Peninsula, Alaska
Links
- Document: Report (pdf)
- Superseding Publications:
- Download citation as: RIS | Dublin Core
Abstract
Nuka Bay is a deep, T-shaped fiord on the southeast coast of the Kenai Peninsula approximately 60 miles southwest of the port of Seward. Gold-bearing quartz veins were discovered in the area in 1918, and between 1920 and 1940 several small mines were in operation around the North and West Arms of the bay. Estimated total production may have been as much as $164,000.
Bedrock in the Nuka Bay area is a thick Cretaceous section of interbedded slate and graywacke that has been regionally deformed into a series of relatively open, but overturned, folds plunging at low angler to the north-northeast. Except at the folds, bedding and foliation (slaty cleavage) are parallel and dip steeply to the northwest. Small granodiorite dikes fill tensional cross joints in the folded sediments, and a few granodiorite sills are intruded along bedding and foliation planes.
Quartz veins are abundant throughout the region, but contain significant amounts of gold only in a relatively small area, 8 miles long and 6 miles wide, around North and West Arms. The veins are generally less than 5 feet wide and 300 feet long and consist chiefly of massive white quartz. Arsenopyrite with minor amounts of other sulfide and native gold occurs as irregular masses and pods in the quartz. The larger and more productive veins dip steeply and strike east-west, almost normal to the regional structure, and appear to be confined to competent graywacke beds or dikes. Random channel sampling of the quartz veins indicates gold values as high as 9 ounces per ton across zones as wide as 2 feet.
A study of the stream sediments throughout the area disclosed several drainages with detectable gold; one, Babcock Creek, contained 0.5 ppm gold, the others from 0.02 to 0.07 ppm. No base metal anomalies were detected. The area appears to warrant further investigation as a potential producer of small amounts of gold. Diligent smell-scale mining may be economically feasible.
Study Area
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | Geology and lode gold deposits of the Nuka Bay area, Kenai Peninsula, Alaska |
| Series title | Open-File Report |
| Series number | 68-229 |
| DOI | 10.3133/ofr68229 |
| Year Published | 1968 |
| Language | English |
| Publisher | U.S. Geological Survey |
| Description | iv, 52 p. |
| Country | United States |
| State | Alaska |
| Other Geospatial | Kenai Peninsula, Nuka Bay area |
| Google Analytic Metrics | Metrics page |